Water-cooled furnace door frame



United States Patent Ottwin L. Braun,

Steel Products Company, tion of Pennsylvania Application February 8,1954, Serial No.

6 Claims. (Cl. 122-499) Pittsburgh, Pa., assiguor to RelianceMcKeesport, Pa, :1 corpora- This invention is for a water-cooled doorframe for use on open hearth furnaces and the like, and is for a doorframe which is provided with an interior chamber or tank for reducingthe destructive or corrosive effects of materials carried into the frameby the cooling water.

Door frames of the type referred to are generally of an arch or invertedU form having two legs which extend down the sides of the furnace dooropening and a bridge across the top. This bridge has a water-cooled noseor lintel projecting laterally from one face thereof, and the bridgeitself extends upwardly in front of the brick work of the furnace abovethe lintel.

The source of water supply for steel plants is frequently from smallstreams or bodies of water that may at times contain considerableforeign material. In the case of small streams the water very oftenbecomes contaminated with algae and other vegetation that is likely toform corrosive acids within the door frame. It also carries aconsiderable amount of oxygen, and may carry various sediment-formingmaterials such as silt. This material most commonly accumulates in thelowest parts of the frame, which in this case are the lower terminals ofthe downwardly-extending legs. It produces oxidation of the steel plateswhich in turn reduces the rate of heat transfer through the metal, andit forms deposits which prevent the free circulation of water, and hencedefeats the purpose of the water. The corrosion of the steel furthermoreeventually weakens the structure, usually at. a place which is quitevital, and interference with cooling allows the exposed metal to beadversely affected by the furnace heat.

The present invention has for its object to provide a door frame of thetype referred to, having a chamber or tank constructed therein designedto trap and retain a considerable part of the materials above referredto and other substances which either form deposits or acceleratecorrosion.

A further object of the invention is to provide in a furnace door ofthis type means for reducing the oxygen content of the water enteringthe more vital parts of the door frame.

These and other objects and advantages are obtained by my invention aswill be hereinafter more fully described.

Generally my invention contemplates the provision within the upper partof such a door frame of a horizontally-extending partition, therebyforming in the upper part of the door frame a separate chamber or tankin which most of the foreign material carried by the cooling water willcollect. Water is carried from this tank through a pipe which has itsupper end opening into the tank at a level elevated above thishorizontal partition into the lower part of the frame and theredistributed in the usual manner, the water finally being led out throughan outlet pipe in accordance with the usual practice. Additionally Iprefer to provide in the chamber or tank above referred to a ferrousbody which is susceptible to oxidation in the environment in which it is'ice employed, and which will first react with the oxygen and corrosivesubstances in the water, thus removing most of the oxygen harmlessly. Itthereby prolongs the useful life of the door frame.

My invention may be more fully understood by reference to theaccompanying drawings, in which:

Fig. 1 is a front elevation of a water-cooled door frame embodying myinvention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a transverse vertical section in the plane of line III-III ofFig. 1; and

Fig. 4 is a fragmentary section on a larger scale than Figs. 1 to 3inclusive, the view being in the plane of line IV-IV of Fig. 1.

Referring to the drawings, the door frame generally is of customaryconstruction, having two depending legs 2 and 3 closed at their lowerends, and having their upper ends opening into and connected by a bridgeor arch 4. The door frame here shown is formed of sheet metal plates,there being a main back plate 5 which is shaped to the contour of thedoor, and which has its edges turned up to form a flange 6. The otherplate 7 is of similar contour and is welded to the flange 6 around allof the edges of the structure, the plate 7 being spaced from plate 5 sothat the door frame is hollow. The plate 7, which faces the brick workof the furnace, has a lintel or nose 8 extending horizontallythereacross, and which is generally in the form of a channel-shapedmember closed at its ends welded to the plate 7 above and below ahorizontally-extending slot 9 in the plate 7.

The construction as herein described is generally known in the art.According to the present invention a horizontal plate 10 is welded intothe space between the plates 5 and 7 at a point above the nose or lintel8. There is thus formed a tank or chamber 11 in the top of the framewhich is separated from the watcrcirculating space under the partition10. At the top of the door frame at one side there is a water inlet pipe12 through which water enters the tank 11.

A vertical pipe which I sometimes refer to as a stand pipe, passesthrough the partition 10 at the center of the door frame, this pipebeing designated 13. It has its upper end well above the partition 10.Its lower end is connected into a T fitting 14, from which lead twobranch pipes 15, one extending down into each of the legs of the doorframe. The pipes 15 are also provided with outlet nipples 16 thatdischarge water horizontally into the nose 8 of the door frame.

At the side of the door frame opposite the pipe 12 an outlet pipe 17passes from the under side of the partition 10 up through the chamber 11and extends above the top of the door frame as shown.

In assembling the frame I prefer to also provide in the chamber 11 aperforate plate 18 formed of some readily oxidizable material. It may,for example, be formed of expanded ferrous sheet metal, and the metalmay be an ordinary low carbon steel. It preferably extends from thepartition 10 to the top of the chamber 11, and may be tack-welded inplace. It is structurally independent of the door frame, andtack-welding is employed only to retain it most effectively in place.

In operation, water is supplied to the door frame through the pipeconnection 12. This water flows immediately into the tank or chamber 11and can spread out and flow in all directions without obstruction. Dueto the large area of the tank or chamber 11 the water will move at a lowvelocity, and at the same time it will become hot. Those materials inthe water that tend to produce corrosion and deposits will tend tosettle out and collect on the plate 10. This is one of the cooler partsof the door frame when the frame is in operation, so that any materialsthat collect on top of the partition will have very little effect on theefficiency of cooling or the life of the door frame. Since the top ofthe pipe 13 is located some distance above the partition 10, the waterwhich flows out of the tank or chamber 11 will not pick up any depositedmaterials from the plate 10, consequently sedimentation can occur abovethe plate 10 and the water will be very materially cleaned before itflows out the pipe 13. When it flows out through the pipe 13, the waterthereafter follows the usual course of water in water-cooled frames ofthis kind, passing down through the distributing system comprising thepipes 15 to the lowermost ends of the legs of the frame, as well as outthe nipples 16 to specially cool the nose 8. The water is dischargedfrom the lower ends of pipes 15 into the hollow interior of the legsclose to the bottom. It will rise from this low point and eventually becarried out through the outlet pipe 17.

By thus trapping most of the sediment-causing materials at a harmlesspoint in the upper part of the frame, sedimentation and the formation ofdeposits at the bottoms of the legs is reduced with the result that thelife of the frame will be substantially prolonged.

Additionally the oxygen carried by the water, or other materials in thewater that tend to corrode the metal of which the frame is constructed,will be brought much more effectively into contact with the expandedsheet plate 18, tending to rust or corrode this plate. This corrosiveaction and rusting will exhaust much of the corrosive substance and freeoxygen from the water, so that the more vital parts of the frame will beprotected from oxidation until the plate 18 has been substantiallycorroded away, or so far corroded as to be further ineffective.

According to my invention there is a clean-out plug 20 at each side ofthe door frame just above the partition 10, so that by unscrewing theseplugs, sediment which accumulates on the plate 20 can be from time totime removed. and material that accumulates on the expanded metal plate18 can be flushed away. The plugs 20 are provided in addition to theusual plugs 21 now commonly employed at the bottoms of the legs 2 and 3.

The interior of the nose 8 of the frame is preferably copper coated. Thecopper coating does not interfere with heat transfer, and resistsoxidation or rusting and is less susceptible to corrosion than the metalof which the door frame is formed. By thus lining the interior of thenose 8 with copper, corrosion at this vital place will be reduced andretarded, while the rate of heat transfer will not be impaired.

Because of the relatively large capacity of the tank 11 as compared tothe size of the pipe 12 and stand pipe 13, the water will flow its area,most of the oxygen and corrosive substances react with this plate 18,instead of reacting with more important and more vital parts of the doorframe. By reason of this, the overall useful life of the door frame willbe substantially increased.

My invention, requiring only the addition of the plate 10 and theexpanded metal sheet 18, and the use of the if anything, to the overallcost furnace design in any way to make use of my invention. My doorframe can be used as a replacement for present frames with no alterationof furnace design, and when these improvements are incorporated, theuseful life of the frame will be substantially extended, and the coolingwater will be more elfectively used throughout the life of the door 5frame.

While I have shown and described one specific embodiment of myinvention, it will be understood that this is by way of illustration,and that various changes and modifications may be made within thecontemplation of my invention and under the scope of the followingclaims.

I claim:

I. A water-cooled furnace door comprising two formed metal plates joinedtogether in spaced relation and forming an arch-like structure with ahorizontal hol is water-tight, a hollow lintel projecting horizontallyfrom one of the plates near the lower edge of the bridge portion withthe interior of the lintel opening into the interior of the bridge, ahorizontal partition inside the bridge above and adjacent the linteljoining the two plates and dividing the interior of the provide asettling tank above the level means for supplying cooling water to thetank, a conduit extending from a level above the bottom of the tanklevel of the upper end of the conduit, and a water disdischarged fromthe interior of the door frame below the said horizontal partition.

end connected to a distributing pipe system that conducts water to thelower portions 40 3. A water-cooled furnace door frame as defined inclaim 1 having corrodible material in the separate tank which isstructurally independent of the door frame and with which oxygen andcorrosive elements in the water may react upon first entering the tankand out of contact with the water after it has entered the said conduit.

4. A water-cooled furnace door frame as defined in claim 1 havingcorrodible material in th separate tank which is structurallyindependent of the door frame and with which oxygen and corrosiveelements in the water may react, said corrodible material comprising avertical perforate sheet of ferrous metal placed edgewise in the tankand extending across the greater portion of the full width of the doorframe.

5. A water-cooled furnace door frame as defined in claim 1 in which saidconduit comprises a pipe passing through the partition with its upperend positioned well above the partition and its lower end connected to adistributing pipe system that conducts water separately to the lowerportions of each of the legs and into the lintel.

6. A water-cooled furnace frame as defined in claim 1 in which oppositeedges of the door frame have removable cleanout plugs at opposite endsof the tank at the level of the top of the partition.

References Cited in the file of this patent UNITED STATES PATENTSKeasbey July 30, 1895 Knox June 26, 1906 Williams Dec. 15, 1931 ChandlerJune 15, 1937 Bates Jan. 11, 1949

